Method of forming and applying cooling fins to tubular members



Ndv. 221, 1944. w BRQNANDER 2,363,224

METHOD OF FORMING AND APPLYING COOLING FINS T0 TUBULAR MEMBERS Filed Aug. 20, 1942 3 Shee ts-Sheet l (Rm I ATT RNEY w. B. BRONANDER 2,363,224 METHOD OF FORMING AND APPLYING COOLING FINS TO TUBULAR M Nov. 21, 1944.

EMBERS Filed Aug. 20. 1942 5 Sheets-Sheet 2 Nov. 2l, 1944. w. B. BRONANDER METHOD OF FORMING AND APPLYING COOLING FINS TO TUBULAR MEMBERS 3 Sheets-Sheet 3 Filed Aug. 20 1942 INVENTOR Braxana ez ATT' N EY Patented Nov. 21, 1944 Maureen the it girl? in we no clirlevrce' r NI-ill! eat? mm 335 "id lie-warranties nil: veil-to t; .ngt li all lit memo '91? 2c -nsm exit at ca. k are an site he galactic. .aacie .cll,

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rittle. The brazing, welde fins to the tubular memexpensive and time cons 1 always result in-a rigid and .for its salient object to e. actical and emcient method 13 mm cooling fin to a tube, "oi-59th znember to be cooled in such nei he .method can be expeditiously result, in forming a gflrm and heat requiring brazing, solfill 23 W objggt the nventionls-toprovide a a cooling fin and cylinderyor: tube inder to, the fine ,will be emciently. conducted of. the invention will appear ged elevationillustrating the thod of .forming the; cooling artial sectional. view: illustrating plied to the groove of acylinder; -a.,yiewsimilar to Fig. 6 but showing wlsimilar to, Fig. 4 butshowing rm of fin construction; 1 l

a view similar to Fig. ,7 but showing wn in Fig. 8 anchored in thewgroove; J n elevation showing, inyedge view, m bf fin embodying the invention; therfin otFig lO s o v n levational view,

e use of expensive patterns view of a strip of .rnaterial shown n compressed and secured in. the

Form G.

tially on line Il -l4 OFFICE A spurned r WUWW WW Wilhelm Iirofianden-Montcla jfsbpiiaaiitajiigta za, f l (on. 29-21-5743)" aconstructed; and, applied thereto accordance with the invention, the cooling fin being wound spirally aroundthe Fig, l3 is a .'diagramm'atic elevational view,

cylinder;

partly -in section. illustrating the method of applying the cooling fin to the cylinder shown in Fig. 12;, 1

Fig.1,14. is a transverse section taken substanof Fig. 13 looking in. the direction of thearrows; i i Fig 15is fan-elevation of the enteringend of the finybent totconform to the curvature of the ri ueisa view similar to Fig."12 but illustrating a cooling fin. construction in which the fin is applied circumferentially around the cylinder but not spirally;

,1;;Fig; ;.17.is\a diagrammatic view, partly in section, illustrating the. method of applying the fin to the cylinder shown in Fig. .16; and Fig ,181isayview similar to Fig. 13 but showing another" form of apparatus for applying the fimto. the cylinder groove.

i-um my l... l t y in section showing an engine cylinder having a cooling fin is provided between walls may be irregular in ter gripping or engaging surface for thefln. The

therein is forced inwardly,

.. The invention briefly described consists of.

forming ajdouble walled cooling fin from a strip of material,:the walls being substantially parallel and beingformed by bending the strip intermediate the longitudinal edges thereof. Material the wallsat the connected edges thereof. and the double wall fin is then applied to a peripheral groove formed in the cylinder, tube or other-member on which the fin islto bemounted. This groove preferably has slightly: confcaved or inwardly flared walls or the form to provide a betgroovemay be. spirally formed on the outer surface of thecylinder or a series of parallel grooves may be formed therein. After the double walled fin isiinserted in the groove with the closed. edge of..thefin disposed at the bottom of the groove, the material disposed at the bend of the fin between xthe wallsis compressed between the bottomot the groove and a bar held against the outer edge of this material. No pressure is appliedwto the outer edges of the fin walls.

As pressure'is'applied, the material between the closed edges of the fin or between the bend thus exerting a lateral pressure: on the inner forcing the walls of the fin of the invention will appear into parallel relation, as shown lustrated inperspective at Fig. 5.

from the following description.

In the particular embodiment of the invention illustrated in Figs. 2-7 inclusive of the drawings. the fin is formed from a substantially flat strip it of suitable material, such as aluminum. This strip is first 'bent or otherwise shaped into the form of an open W as shown in Fig. 2, comprising walls It and i1 and an intermediate inverted y-shaped portion ll The walls arenext bent in 8.,and the portion I8 is then compressed, as shown in Fig. 4, to form the double'walled fin.

The cooling fin maybe applied to a cylinder wall 20 of an internal combustion engine. as-

shown in Fig. 12. The outer surfaceof thecylinder wall has formed therein a spiral groove 2|, the walls of the groove, as shown in Figs. 6 and 7, being preferably slightly concaved, as shown at 22.

. The closed edge or bend of the double walled :fin is inserted in the groove II of the cylinder wall 20. the cylinder preferably being mounted and rotated in the direction of the arrow shown second roller 29 guides the stripl'l and prevents the strip from being thrown upwardly or auto! alinement.

If desired. the fin may be placed in the groove or W has thereiniab'ar IQ of deformable material, preferably metal. As the portion 4' is compressed in the man- Iner hereinbefore described, the fin walls are spread or forced laterally into close, gripping en- :agement with the groove walls, as shown in Fig.

lnl igslfiandllthebarllistaperedandmay be of harder material or metal.- As the portion in Fig. 13. .The. entering end of the fin may, if

desired, be initially secured in the groove by manually tamping the outer end 25 of the portion l8 of the fin,the tamping pressure being exerted in a direction toward the base of the groove 2 I. This pressure forces the material in thenon-radiating portion it of the fin'into the groove and forces the inner end portions 26 and 21 of the walls It and I1 laterally into the concaved, irregular or deformed walls 22 ofthe groove, thus firmly anchoring the fin in the groove and formof the fin is compressed, the fin walls are forced laterallyto gripthewallsof the groove.

Although particular mention has been made of applying the fin to a cylinder or tube, it should be understood that the method maybe used equally well in a plyin a ool fln'to any M 6mber tobe cooled.

. From the foregoing description it will beevident that asimple, practical and. efiicient method of forming and applying a cooling fin to a tube or cylinder has been worked out and that this method will provide a connection or joint between a the fin and the cylinder or tube that will firmly ing a ti ht ipping engagement with the walls of the groove.

After the entering portion of the strip ha thus. I

been anchored, theremaining portion l8 of the strip is forced into the groove by pressure hetween a fiat strip 29 and the bottom of the groove 2|. Strip 29.1s disposed between the walls It and ll of the fin and held down in operation by a roller 28 and in engagement with the portion 24 of the inverted V it of the cooling fin. A second rollertli guides the strip and holds. it in position. The strip 29 may also be used to initially anchor the strip instead of the manual tamping. The fin is preferably initially bent as shown in Fig. 15, to conform at itsentering end a to the curvature of the groove.

It will be evident that as the cylinder or tube is rotated in the direction of the arrow, the double walled cooling fin will be drawn into the spiral groove, it being understoodthat the cylinder is free to move longitudinally as the cooling fin is wound spirally in the groove 2| and that no pressure is exerted on the outer edges of the fin walls It and I1.

I; desired, the cylinder wall 35, a shown in Fig. 16, .may be provided with a series of parallel grooves 36 instead of with a spiral groove as shown in Fig. 12. With this form of construction, a series of parallel cooling fins is secured to the cylinder in the manner shown in Fig. 17. In this form of construction the entering end of the cooling fin is secured in the same manner as that above described and pressure on the portion 25 of the cooling fin is exerted between a flat strip 21 similar to the strip 29 shown in Fig. 13 and the bottom of the groove. This strip is forced between the walls It and ll of the cooling fin and against the portion 25 thereof byspressure roller 38 similar to the roller 28 shown in Fig. 13. A

anchor the fin in position and efficiently conduct the heat from the cylinder to the fin.

Although certain specific embodimentsof the invention have been particularly shown and described, it will be understood that the method is not limited to the particular details set forth or to the apparatus but that changes in the method may be made without departing from the spirit or scope of the invention as expressed in the following claims. v What I claim is:

'L'The method of forming and-securing a radiating fin to'a member which consists of forming a strip of material intermediate the longitudlnal edges thereof to form substantially parallel connected walls, forming a groove'in the member, inserting the closed edge of the double walled fin in said groove, the inner connected edge of the double walled fin being formed of folded material integral therewith and folded back against the walls and substantially filling the space between the walls at the inner edge thereof, and forcing the inner portions of said fin walls laterally into tight gripping'engagement with the walls of the groove by pressure against said folded material between the fin walls and between the bottom of the groove and inwardly acting pressure means.

2. The method of forming and securing a ra- I groove walls by pressure exerted against the portion of the W intermediate the fin walls.

3. The method of providing a member withradiating fins'which consists of forming a plurality of grooves in the member, forming double walled the fin walls may be compressed by fln units with substantially parallel, spaced walls connected at one edge of each wall by a bridge of compressible material integral with the walls extending outwardly from the inner edges oi the walls and substantially filling the space therebetween at the connected edge portions to be inserted in the grooves. inserting the connected edge of a fin unit in each groove, and forcing said walls laterally by pressure against the outer portion 01' said compressible material directed toward the base of the groove to compact the compressible material and to anchor the walls in the grooves.

4. The method of providing a member with radiating fins which consists of forming a plurality of grooves in the member, forming double walled fin units with substantially parallel, spaced walls connected at one edge of each wall by folded compressible material integral with the walls and extending in a direction toward the outer edges of said fins and substantially filling the space therebetween at the connected edge portions to be inserted in the grooves, inserting the connected edge of a fin unit in each groove, and forcing said walls laterally by pressure against the outer portion of said compressible material directed toward the base of the. groove to compact the compressible material and to anchor the walls in the grooves.

5. The method of forming and securing a radiating fin to a grooved member to be cooled which consists oi inserting in the groove substantially parallel fin walls, the bottom portion of each wall having an integral portion folded back against said wall, said folded portions substantially filling the space between the bottom portions of the walls disposed between the walls of the groove and forcing the fin walls laterally into tight gripping engagement with the groove walls by inward pressure directed against'said folded portions.

WILJ-IELM B. BRONANDER. 

